it's pretty basic as long as you know what you're doing.
first decide what you want in terms of ram, video card, and cpu.
then find a nice motherboard that suits your needs. be sure to consider things like the number of USB ports, SATA plugs, etc.
next, consider drives - hdd and optical.
once you've got all that, figure out how strong a PSU you'll need. don't forget that a lot of graphics cards these days are not powered through the mobo, but through a separate connection to the PSU. and don't go cheap on the PSU! it's one of the most important parts of your machine!
case comes last. not sure why you need a manual for it though, it's just a box
unless you want one of those fancy ones with an LCD temp display or something...
as for building it, you're right - snap snap and it's done. you can go from opening boxes to installing your OS in under an hour.